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RS BIT P2.4 ;這3位是液晶屏的控制信號(hào),連接方式由具體硬件而定 RW BIT P2.5 E BIT P2.6 ORG 00H AJMP MAIN MAIN: mov R0,#24 ACALL INITIAL ACALL DISPLAY;調(diào)用液晶顯示子程序 AJMP MAIN ;-------液晶顯示--------------------------------------- DISPLAY: MOV A,#80H ;第一行第1 個(gè)點(diǎn) ACALL WR_CMD MOV DPTR, #LINE1 ACALL PR_STR ACALL WR_DATA DISP1: MOV A,#18H ;字符左移命令（注：實(shí)物中左移命令字為18H） ACALL WR_CMD ACALL D05S DJNZ R0,DISP1 RET ;---液晶屏初始化------------------------------------------------- INITIAL: MOV A, #01H ACALL WR_CMD MOV A, #38H ACALL WR_CMD MOV A, #0CH ACALL WR_CMD MOV A, #06H ACALL WR_CMD RET ;----寫液晶指令的子程序------------------------------------------ WR_CMD: MOV P0, A CLR RS ;寫入控制命令 CLR RW CLR E ACALL DELAY SETB E RET ;----寫液晶數(shù)據(jù)--------------------------------------------- WR_DATA: MOV P0, A SETB RS ;寫入數(shù)據(jù) CLR RW CLR E ACALL DELAY ;判斷液晶模塊是否忙? SETB E RET ;-----寫行字符--------------------------------------------------------------- PR_STR: CLR A MOVC A, @A+DPTR JZ END_PR ACALL WR_DATA INC DPTR AJMP PR_STR END_PR: RET ;----查看液晶忙碌信號(hào)--------------------------------------------------------- DELAY: MOV P0,#0FFH ;判斷液晶顯示器是否忙的子程序 CLR RS SETB RW CLR E NOP SETB E JB P0.7,DELAY ;如果P0.7為高電平表示忙就循環(huán)等待 RET ;----0.5S延時(shí)(按12MHZ算)----------------------------------------------------------------- D05S: MOV R6,#25 MOV R5,#100 MOV R4,#100 DJNZ R4,$ DJNZ R5,$-4 DJNZ R6,$-8 RET ;-------------------------------------------------------------------------------------- LINE1:
DB 'Happy birthday to you!'
END
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